Researchers at the Life Sciences Institute of the University of Michigan, in the United States, have found that the genetic junk (the “junk” DNA or satellite DNA) plays a vital role in ensuring that chromosomes are organized correctly within a cell’s nucleus, which is crucial for survival.
The satellite DNA consists of extremely simple and repetitive genetic code sequences. Although it is a large part of our genome, this DNA does not contain instructions to make certain proteins, according to the researchers.
Moreover, the repetitive nature makes the genome less stable and more susceptible to disease. Until recently, scientists believed that “junk” genes had no real purpose.
“But we were not convinced by the idea that this is just a genetic waste,” said Yukiko Yamashita, lead author of the study. “If we do not need it [junk DNA], and if it does not give us any advantage, then evolution would have eliminated it. But this has not happened.”
Researchers found that the junk DNA has important roles in Drosophila and mice
Researchers have removed the D1 gene, a protein that binds this satellite DNA, from the Drosophila Melanogaster species of flies. Thus, the scientists have discovered that the so-called “germ cells”, which become sperm or eggs, die as a result of the removal of the D1 gene.
Analyzes have revealed that cells that died formed micro-nuclei that included parts of the nucleus’ genome.
Without the entire genome encapsulated in the nucleus, the cells could not survive. Also, the team conducted similar experiments on mice, which returned the same result.
The similarity of the results made scientists believe that the junk DNA that was thought to be useless still has an important role to play in other organisms, so it might also have a great importance in humans but more research in this regard is needed.